ObjectiveTo investigate the correlation of spontaneous YMDD mutation in different hepatitis B virus (HBV) genotypes with HBV-related hepatocellular carcinoma (HCC). MethodFrom May 2010 to May 2012, 110 HBV-related hepatocellular cancer patients not treated by anti-virus drugs and 1 079 chronic HBV infectors (including asymptomatic HBV carriers, chronic hepatitis B patients, and HBV-related liver cirrhosis patients) were included in our study. HBV YMDD mutation was detected by fluorescence hybridization bioprobe polymerase chain reaction (PCR) and melting curve assay using Diagnosis Kit for HBV YMDD Mutation (Qiagen Biotechnology). Serum HBV genotype was detected by real time PCR using genotype specific TaqMan probe. According to data type, t-test, χ2-test and unconditional logistic regression were used for statistical analysis. ResultsIn the HCC group, genotype C virus, spontaneous YMDD mutation and genotype C virus with YMDD mutation were detected in 39 patients (35.5%), 16 patients (14.5%) and 14 patients (12.7%), respectively. In the chronic HBV infection group, HBV genotype C virus, spontaneous YMDD mutation and genotype C virus with YMDD mutation were detected in 153 patients (14.2%), 46 patients (4.3%) and 17 patients (1.6%), respectively. The difference between the two groups were statistically significant (χ2=33.368, P<0.001; χ2=21.353, P<0.001; χ2=48.889, P<0.001). Unconditional logistic regression analysis suggested that infection of genotype C virus and genotype C virus with spontaneous YMDD mutation might be important risk factors for the development of HCC[OR=2.943, 95%CI (1.778, 4.872), P<0.001; OR=5.989, 95%CI (2.394, 14.980), P<0.001]. ConclusionsInfection of genotype C virus with spontaneous YMDD mutation is tightly related with the occurrence of HCC and has important value for earlier warning of HCC.